A short selection from Essay Fifteen in Darwin, Dogen, and the Extremophile Choice.
A bird might marry a fish, but where would they live? —Tevye character, in Fiddler on the Roof
For the need of a niche, or for the good of a ‘race’, sexual traits intensify the cut of new species, just as they call out the daily pageant of who’s who in the forest. In fact, when we enter here we really don’t get to see much of the inter-feeding that gives a niche its practical meaning (this might not be as true for a pre-human forest, or for an ecosystem that’s been rewilded, but we’ll come back to this in Part V). Instead, we are overwhelmed by a sensory feast of colour, and music, and erotic fragrance that binds both visitor and resident alike in its spell. This show, announcing the whereabouts of both mate and prey, contributes nothing to the immediate survival of its participants. In fact, we could say mating display is genetically scripted in defiance of death by a complementary selection process; one with the larger purpose of ‘asserting’ species integrity and ‘shepherding’ further speciation.
My active wording here touches on an old ecological mystery. The dense tangle, and even overlap, of ecological speci-fications found in ancient and evidently undisturbed ecosystems, like the Amazon rainforest, seems incredible when we treat Gause’s Law (One Species, one niche, through competition for resources) like… well, like “trial without a jury”.  The mystery gets even deeper (says Paul Colinvaux, who collected much of the evidence for a surprisingly old and undisturbed Amazon) if we’ve been taught that a history of geographic isolation is a necessary precondition for speciation at all.  But, and here’s my point, if we recognize that sexual selection within superfluously large populations can lead to the definition of species by genetic ‘convention’, then we can touch the mystery at a more personal level. We might even be excused for imagining that the super-speciated Amazon was ‘Pan-piped’ into existence!
Some questioning of a patently inadequate ‘Law’ is of course always in order, but for me to conjure a whole new Transcendental Being (“Old Buddha”) to take its place contravenes Occam’s razor. (Gause and Occam really gave us only principles, not laws.) So how about we allow the same sense of truth to peek through here that we allow when we are faced with our own ‘hard problem’; that is, the mind-body problem: why and how does a body have qualia or phenomenal experiences?  Ultimately, the mind feels like body (as does the ‘thought’ of their separation).
When we sit in mindfulness/insight meditation, we may notice that a conscious intention, in its phenomenological essence, feels like a rather strong ‘inclination’ that’s been further reinforced by words. So if we can say species are inclined to reproduce their kind, then we can also say that Nature is literally in-tending when it reproduces, or establishes, ecological fitness further reinforced by sexual selection. Sexual traits now become the ‘words’ in the story of evolution, for they define and elaborate species as ‘gestures’ that point reproductive behaviour toward proven fitness in the real world. Sexual traits guide organisms to reproduce established species, just as words guide our thinking to reproduce established ideas.
1. “… as a result of competition two similar species scarcely ever occupy similar niches.” —Georgii Frantsevich This quote is taken from: Krebs, Charles, J. 1972. Ecology: The Experimental Analysis of Distribution and Abundance. New York: Harper & Row. p. 231. Also see: https://www.extremophilechoice.com/2020/07/27/one-species-one-niche-why-humans-destroy-nature/
2. Colinvaux, Paul A. 2007. Amazon Expeditions: My Quest for the Ice-Age Equator. New Haven, CT: Yale University Press. pp. 121-122. Also see: https://www.extremophilechoice.com/2022/05/30/old-buddha-speaks-part-1-sexual-traits-are-words/ Note 2 in this link reads: The original view of speciation assumed a certain degree of geographical isolation between two populations of a single species, which allowed for character displacement, followed by renewed contact; and from here it was supposed that competitive exclusion takes over. Throughout this book I am favouring a view closer to Paul Colinvaux’s (2007, pp. 121-122.) which gives far more credit to the subtlety of co-evolution. Isolation needs not be so crudely “geographical” in very large and complex ecosystems. It is still generally assumed that novel traits favouring the exploitation of new resources, at the expense of more species-typical resources, will get quickly diluted by the interbreeding of a large population. But it was demonstrated by Patrick Bateson as early as 1982 (Gould, 1995, pp. 379-380, “The Great Seal Principle”) that sexual selection goes beyond the establishing of overt traits to ensure advantageous mating; and in fact a general rule for perhaps all sexual species is “maximal attraction to intermediate familiarity”. It’s understandable that avoidance of breeding with close family is adaptive, but why is mating with intermediate family more adaptive than mating with more distant relations, unless selection for racial disparity is at play here? Nature seems to have evolved ways to get around even “novelty dilution”, so who are we to insist on a model of speciation simply because it’s crude enough for us to represent?
3. David Chalmers coined the name “hard problem” (1995, 1996), but the problem is not wholly new, being a key element of the venerable mind-body problem. Still, Chalmers is among those most responsible for the outpouring of work on this issue.